(1) Field of the Invention
The present invention relates to an ink-jet printer system in which a common ink-jet printer is shared by a multiple number of host machines.
(2) Description of the Prior Art
In general, if an ink-jet printer has been unused for a long period, the viscosity of ink increases due to ink drying at the nozzle portion of the ink head, inducing failure to eject ink and nozzle clogging. Therefore, a necessary recovery treatment such as cleaning of the ink-jet head is needed before a printing operation after a lapse of a long period of inactivity of the printer.
If, however, this recovery treatment is performed each time a printing operation is started or at other timings regardless of the duration of the inactive time, an unnecessary recovery treatment may be done despite that the inactive time is short. In such an event not only is the completion time of the printing operation delayed by the execution of unnecessary recovery treatment, but also the ink and electric energy used for the recovery treatment are consumed wastefully.
In order to solve this problem, Japanese Patent Application Laid-Open Hei 7 No. 009686 discloses a technology in which output of warning information and a necessary recovery treatment are performed in accordance with the inactive time of the ink-jet printer so as to suppress the time required for the recovery treatment and the consumption of ink. The technology of this publication, however, is proposed assuming a system for an electronic device including a dedicated printer, that is, a system which is made up of a single electronic device and a single ink-jet printer.
With the recent prevalence of personal computers and development of networking, there is an increasing tendency toward use of systems in which a single ink-jet printer is shared by a multiple number of host machines(personal computers, electronic devices and the like). In such a system, it is possible for each host machine to memorize when the ink-jet printer was used but it is impossible to know the usage status of the ink-jet printer from other host machines. Therefore, when a single ink-jet printer is shared by multiple host machines, it has been difficult for each host machine to precisely determine the inactivity time of the ink-jet printer.